The present invention relates to a hand power tool which has a housing with air inlet and air outlet openings.
More particularly, it relates to such hand power tool in which the openings are arranged in different regions of the housing, so that they have different directions.
In electrically operated hand power tools, for example in screwing tools, drills, drill or impact hammers, saws, grinders, etc., fans as a rule are arranged for cooling the motor and the transmission by aspirating cold air through the openings in the housing or blowing hot air outside. As disclosed for example in the German patent document DE 196 26 245 A1, the air inlet or the air outlet openings are distributed around the housing of the hand power tool, so that the openings have different directions. This means that during the operation of the hand power tool in each point of time air is aspirated or blown out around the housing through all openings, or in other words from all directions or to all directions.
In individual applications of the hand power tools, it can however be disadvantageous when air is aspirated or blown from several sides into the housing or out of the housing. The reason is that it is uncomfortable when the operator of the hand power tool is subjected to hot air in the sight of view or on his body. It is therefore desirable that, depending on whether the operator is left handed or right handed, air be not blown to the direction associated with the operator. It is also disadvantageous when air is aspirated into or blown from the housing in the vicinity of dust or chips to produce a flow with dust or chips, which can be extremely detrimental to the operator.
Accordingly, it is an object of the present invention to provide a hand power tool in which air inlet openings and air outlet openings of the housing are oriented so that the air aspirated or blown out during the operation of the power tool does not act in disturbing manner.
In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a hand power tool in which on the housing a movable cover is provided, for closing a part of the openings facing in various directions.
When the hand power tool is designed in accordance with the present invention, then with simple means the direction of the air inlet and air outlet openings can be changed so that the aspirated or blown air is not disturbing during the operation of the hand power tool.
In accordance with another advantageous feature of the present invention the openings on the housing are arranged so as to have a ring-shaped circumferential track, and the cover is formed as a strip of an elastic material which is displaceably supported on the track and surrounds the ring-shaped track only partially.
In accordance with still a further feature of the present invention, it is advantageous when the strip which forms the cover is guided with its edges in grooves, which are formed in the housing at both sides of the ring-shaped track.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.